1. Field of the Invention
The present invention relates to an extendable torch guide and, more particularly, to a torch guide including an extendable cutting rail and a slidable torch tip holder for use in the cutting of structural and plate steel.
2. Description of the Prior Art
Structural and plate steel typically comes in large sheets which must be cut for use in the fabrication of structural members. Cutting is typically done with a torch in a large fabrication shop. The cutting torches are typically controlled by automatic or semiautomatic cutting equipment which insures that cuts are made on a straight line and with the torch tip maintained at a desired angle and distance from the metal plate.
On the other hand, small fabrication shops often do not have this sophisticated cutting equipment and metal plate cutting must be performed by hand. Furthermore, cutting is often done in the field, at a work site, or for repairs, where sophisticated cutting equipment is unavailable.
In cutting metal plates with a cutting torch, several requirements exist. Initially, it is necessary that cuts be made as straight as possible. Secondly, it is necessary that a cut be as consistent as possible, with the torch tip being maintained at a fixed distance from the metal plate. One of the most difficult requirements is the necessity for cutting at an angle, typically 371/2.degree., the standard bevel used when preparing a metal plate for subsequent welding, although other angles up to 60.degree. are also used, depending on the thickness of the metal plate.
In an attempt to satisfy the above requirements, a variety of torch guides have been provided. A typical torch guide includes an elongate cutting rail or straight edge having a plurality of magnets attached thereto so that the straight edge can be attached to a metal plate. The straight edge provides a guide for making a straight cut.
Several problems are encountered in the use of such a torch guide. First of all, the torch guide typically has a fixed length and, therefore, can only be used to make a continuous cut having such a length. If a longer cut is necessary, the torch guide must either be moved or extension members attached thereto. The former approach is undesirable because of the necessity of accurately aligning the new position of the straight edge with the old position thereof, and the latter is undesirable because of the necessity of carrying additional, separate parts.
Secondly, even with such a torch guide, there is no guarantee that an even, consistent cut will be made because the guide relies on the skill of the operator in maintaining the torch tip at a fixed distance from the metal plate. An additional means, as well as the skill of the operator, is also required when making a beveled cut in preparing a metal plate for a subsequent welding operation.